How do fish maintain neutral buoyancy?

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Transcript of How do fish maintain neutral buoyancy?

Different kinds of fish have 4 different ways of achieving neutral buoyancy.

“Bony fish achieve neutral buoyancy through an air filled sac called the swim bladder. The swim bladder controls the fish’s buoyancy by varying the gas pressure inside the fish’s body to allow it to sink or rise in the water.”Background InfoHow do fish maintain neutral buoyancy?Cartilaginous fish (sharks, rays) do not have swim bladders. Instead, they achieve neutral buoyancy by...

1.Storing lipids throughout their body.

Reduction of blubber.

Dynamic lift.

Sharks generate lift with their swimming motion. (This is why a shark’s fin is so important to a shark. They need it to swim)Background InfoHypothesis: If I vary the static lift of an object using the same methods that different fish use to achieve neutral buoyancy, then the object will be able to do the same as the fish, because...they are given similar circumstances.Hypothesis & VariablesMaterials List-Big bowl (2)-Water-Pitted Olives (5)-Shortening / Margarine-Balloons (3)-Cod Liver Oil-Tea Spoon-Popsicle Stick(3)-Bathtub-Rope

Materials ListExperiment 1 ProcedurePrepare 5 pitted olives, margarine or shortening, and a big bowl full of water. Then put different amounts of shortening or margarine into the olives.Drop the olives into the bowl filled with waterSee if the olives maintain neutral buoyancy.This test is for the method of storing lipids.Experimental DesignExperiment 2 ProcedurePrepare 3 balloons, a 3 popsicle sticks, rope, and a big bowl full of water or a bathtub.Blow each balloon to a different sizeTie each balloon to a stick. Drop the balloons tied to the stick into the bowl of water. See if the balloons maintain neutral buoyancy. This test is for the method of the swimming bladder.Experimental DesignExperiment 3 ProcedurePrepare a normal 500ml water bottle, cod liver oil, and a teaspoon. Take the teaspoon and fill it with cod liver oil.Add the cod liver oil in the teaspoon into the water bottle. Keep adding until neutral buoyancy is reached.This test is for the method of reducing blubber.Experimental DesignData AnalysisIndependent: water, bathtub, rope lengthDependent: olive, popsicle stickControl: amount of margarine, balloon size, amount of cod liver oilData AnalysisConclusionThe purpose of this lab was to test if the other objects could maintain / achieve neutral buoyancy if given similar characteristics as the fish. My results to test if this is correct failed, however. Out of 3 experiments 1 succeeded half way and the other two failed completely. Therefore I reject my hypothesis. The only thing that could’ve possibly gone wrong with the experiments was with the balloon experiment. I think the balloon size and the size of the stick didn’t quite match up. The balloons were all different sizes, but the sticks were all the same size. Other than “How do fish maintain neutral buoyancy”, I would like to know about “How do fish that live at the bottom of the ocean not get crushed by the pressure?QuestionsDo cartilaginous fish have swim bladders?YES1. Yes2. No3. MaybeHow do bony fish maintain neutral buoyancy?A. Reduction of lipids. B. Dynamic LiftC. Swim BladderD. Reduction of BlubberSWIM BLADDERWhich one of these is a method for bony fish to maintain neutral buoyancy?A. Swim bladderB. Storing lipidsC. Dynamic LiftSWIM BLADDERWhich one of these are cartilaginous fish?A. GoldfishB. Salmon C. Shark D. OctopusSHARK